Temporal and spatial response characteristics of evapotranspiration to soil water content in Qinghai Lake Basin
Studying the spatial and temporal response characteristics of evapotranspiration to soil water content aids in comprehending regional hydrological cycle processes.The 8-day,monthly,and annual variation charac-teristics and corresponding relationship between evapotranspiration and soil water content in Qinghai Lake Basin were investigated from 2016 to 2020 by remote sensing data and spatial analysis,mathematical and statistical methods of ArcGIS,which would reveal the spatial and temporal response.The results indicated that:(1)From 2016 to 2020,the average evapotranspiration and soil water content in the Qinghai Lake Basin were 494.45 mm and 0.34 m3·m-3,respectively.The 8-day,monthly,and annual evapotranspiration showed an increasing-then-de-creasing trend,while the soil water content showed the increasing-decreasing-increasing-decreasing,increase-steady-decrease and comparable stable characteristics.(2)The average evapotranspiration across all time scales generally decreased from the northeast to the southwest of Qinghai Lake Basin.Additionally,the average soil wa-ter content increased from the lakeshore to the perimeter of the watershed and from the valley to the sides.(3)There is a temporal synergism between evapotranspiration and soil water content during the 1st-185th days(Janu-ary-June)and the 241 st-365th days(September-December),which is stronger than that during the 185th-241th days(July-August).This synergism during the non-growing season is also stronger than the growing season,and stronger in 2016-2018 than in 2018-2020.Additionally,spatial synergies were found to be stronger in the northeast of Shaliu River Basin and Haergai River Basin and the eastern shore of Qinghai Lake than in other ar-eas.(4)The correlation coefficients between evapotranspiration and soil water content were calculated at differ-ent temporal scales.The coefficients were 0.61,0.69,0.36 and 0.24 for the 8-day,monthly,non-growing sea-son and growing season scales,respectively.The spatial result showed significant positive correlations,indicat-ing that the temporal response of evapotranspiration to soil water content was stronger at the monthly and 8-day scales.In addition,the results showed that evapotranspiration increased with the increase of soil water content in different time.The results of this study can provide theoretical reference for understanding the hydrological cycle process,water balance and water resources management in Qinghai Lake Basin.
evapotranspirationsoil water contenttemporal and spatial response characteristicsQinghai Lake Basin
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